Advocate for the horse argument is here: Advocate For The Horse or (PDF version here)
Video series is here: Horses Need Shade (video proof)
The great philosopher, Sarcasticus said, "The only animals that do not need shade are the humans that fail to provide shade for their tied or pent up animals. Those people are impervious to hot sun and never need shade. Yet, they take as much shade as they can get. Why?" A similar sentiment was asserted by the great contradictory sage, Ridiculopothes.